1. Field of the Invention
This invention relates to a method and an apparatus for digital communications using, for example, channel information in digital TV translator.
2. Background of the Related Art
A digital TV translator is to provide service to a wave shadow area where a digital broadcasting transmitter cannot be reached. Thus, the digital TV translator increases the broadcasting area of the digital TV. The digital TV translator receives a weak broadcasting signal transmitted from the digital broadcasting transmitter and demodulates the received signal thereof before converting it to a base-band of an intermediate frequency. The converted signal is demodulated again to a desired channel frequency and amplified to a signal that subscribers of the wave shadow area can receive.
FIG. 1 shows a related art digital TV broadcasting transmitting system that includes a digital TV translator. Referring to FIG. 1, a digital broadcasting transmitter 100 transmits a broadcasting signal with an F1 frequency. Generally, the digital broadcasting transmitter 100 is placed in elevated areas, such as a mountain or a tall building, to transmit the digital broadcasting signal to the subscribers.
When the digital broadcasting transmitter 100 transmits the broadcasting signal, a subscriber located in the surrounding areas of the digital broadcasting transmitter 100 can directly receive the broadcasting signal through an antenna placed on a roof, a built-in TV antenna or the like. However, those subscribers living in the shadow area with obstacles such as the mountain or the hill or those subscribers distant from the digital broadcasting cannot receive the broadcasting signal transmitted from the digital broadcasting transmitter 100. As a result, digital TV translators 101 to 104 are positioned to translate the broadcasting signal received from the digital broadcasting transmitter 100 using an F2 frequency or an F3 frequency. In addition, digital TV translators 105, 106 can translate a broadcasting signal transmitted from the preceding digital TV translators 103, 104.
Each digital TV translator 101xcx9c106 demodulates the broadcasting signal transmitted from the digital broadcasting transmitter 100, and converts into the base-band signal prior to performing an error-correction process. Then, the demodulated signal therein is re-modulated and amplified, and transmitted to the subscribers located in the area where direct transmitting cannot be established. Since the converted base-band signal is identical to the data generated during the transmitting process from the digital broadcasting transmitter 100, it has an identical quality to the broadcasting signal. Therefore, even if the digital TV translators 101xcx9c106 repeatedly transmit the broadcasting signal to reach subscribers using a channel different from the channel used by the digital broadcasting transmitter 100, the uniform signal quality can be maintained.
However, as described above, the related art digital TV broadcasting transmitting system has various disadvantages. Since the related art digital TV translators 101xcx9c106 translate the broadcasting signal to the subscribers using channels different from the channels used by the digital broadcasting transmitter 100, the actual channel information received by the digital TV of the subscribers is different from that of the channel information stored in the received broadcasting signal. Therefore, instabilities may occur in the subscriber""s digital TV during the processing of the received broadcasting signal. As a result of such instabilities, stable digital TV broadcasting may not be established.
The above references are incorporated by reference herein where appropriate for appropriate teachings of additional or alternative details, features and/or technical background.
An object of the present invention is to provide an apparatus and method for operating a digital communication system that substantially obviates one or more problems caused by disadvantages of the related art.
Another object of the present invention is to overcome the disadvantage of related art methods by providing a method and an apparatus for modification of the channel information in the digital TV translator that can modify the transmitted channel information of the broadcasting signal according to the transmitted channel information being used by the digital TV translator.
Another object of the present invention is to provide a method and an apparatus for modification of channel information in digital TV translator where if a broadcasting signal is transmitted using a transmitting channel different from a receiving channel, the channel information stored in the broadcasting signal can be appropriately modified according to the transmitting channel.
In order to achieve at least the above-described objects of the present invention in a whole or in parts, there is provided a method of processing information in a digital translator of a digital system that includes detecting a data frame start time of a data frame from a received digital broadcasting signal, determining whether channel information stored in the detected data frame is identical to prescribed channel information, and modifying the channel information stored in the data frame according to the prescribed channel information when the channel information stored in the data frame is not identical to the prescribed channel information.
To further achieve at least the above-described objects of the present invention in a whole or in parts, there is provided a method of processing channel information in a digital TV translator that receives a digital broadcasting signal that includes checking a frame start position of a MPEG-II transport stream by searching a synchronization bit, wherein the MPEG-II transport stream is extracted from the digital broadcasting signal, searching an identification data field value of the MPEG-II transport stream to determine whether the identification data field value is a prescribed value, determining whether channel information stored in a transport stream identifier field of the MPEG-II transport stream is identical to a specified channel information when the identification data field value is the prescribed value, modifying the stored channel information of the MPEG-II transport stream by inserting the specified channel information to the transport stream identifier field when the stored channel information is not identical to the specified channel information, and modifying error-correction data of the modified MPEG-II transport stream when the stored channel information is modified.
To further achieve at least the above-described objects of the present invention in a whole or in parts, there is provided a digital TV translator that receives a digital broadcast signal that includes a shifter that receives data extracted from the digital broadcast signal, a controller coupled to the shifter that modifies channel information in the received data according to prescribed channel information when an identification data field value of the received data is a prescribed value, an error-correction generator coupled to the controller that modifies an error-correction bit in the received data based on a control signal of the controller and the identification data field value, a channel information input device coupled to the controller that supplies the prescribed channel information to the controller, and an encoder that encodes the received data outputted by the shifter and the modified received data outputted by the flow controller for transmission to a transmitting terminal of the digital TV translator.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objects and advantages of the invention may be realized and attained as particularly pointed out in the appended claims.